<?php
    // +----------------------------------------------------------------------
    // | ThinkPHP [ WE CAN DO IT JUST THINK ]
    // +----------------------------------------------------------------------
    // | Copyright (c) 2006~2017 http://thinkphp.cn All rights reserved.
    // +----------------------------------------------------------------------
    // | Licensed ( http://www.apache.org/licenses/LICENSE-2.0 )
    // +----------------------------------------------------------------------
    // | Author: liu21st <liu21st@gmail.com>
    // +----------------------------------------------------------------------
    namespace think\model\relation;

    use think\db\Query;
    use think\Exception;
    use think\Loader;
    use think\Model;
    use think\model\Relation;

    class MorphMany extends Relation {
        // 多态字段
        protected $morphKey;
        protected $morphType;
        // 多态类型
        protected $type;

        /**
         * 构造函数
         * @access public
         * @param Model  $parent    上级模型对象
         * @param string $model     模型名
         * @param string $morphKey  关联外键
         * @param string $morphType 多态字段名
         * @param string $type      多态类型
         */
        public function __construct(Model $parent, $model, $morphKey, $morphType, $type) {
            $this->parent    = $parent;
            $this->model     = $model;
            $this->type      = $type;
            $this->morphKey  = $morphKey;
            $this->morphType = $morphType;
            $this->query     = (new $model)->db();
        }

        /**
         * 延迟获取关联数据
         * @param string   $subRelation 子关联名
         * @param \Closure $closure     闭包查询条件
         * @return false|\PDOStatement|string|\think\Collection
         */
        public function getRelation($subRelation = '', $closure = null) {
            if ($closure) {
                call_user_func_array($closure, [& $this->query]);
            }
            $list   = $this->relation($subRelation)->select();
            $parent = clone $this->parent;
            foreach ($list as &$model) {
                $model->setParent($parent);
            }
            return $list;
        }

        /**
         * 根据关联条件查询当前模型
         * @access public
         * @param string  $operator 比较操作符
         * @param integer $count    个数
         * @param string  $id       关联表的统计字段
         * @param string  $joinType JOIN类型
         * @return Query
         */
        public function has($operator = '>=', $count = 1, $id = '*', $joinType = 'INNER') {
            throw new Exception('relation not support: has');
        }

        /**
         * 根据关联条件查询当前模型
         * @access public
         * @param mixed $where 查询条件（数组或者闭包）
         * @return Query
         */
        public function hasWhere($where = []) {
            throw new Exception('relation not support: hasWhere');
        }

        /**
         * 预载入关联查询
         * @access public
         * @param array    $resultSet   数据集
         * @param string   $relation    当前关联名
         * @param string   $subRelation 子关联名
         * @param \Closure $closure     闭包
         * @return void
         */
        public function eagerlyResultSet(&$resultSet, $relation, $subRelation, $closure) {
            $morphType = $this->morphType;
            $morphKey  = $this->morphKey;
            $type      = $this->type;
            $range     = [];
            foreach ($resultSet as $result) {
                $pk = $result->getPk();
                // 获取关联外键列表
                if (isset($result->$pk)) {
                    $range[] = $result->$pk;
                }
            }
            if (!empty($range)) {
                $data = $this->eagerlyMorphToMany([
                                                      $morphKey  => [
                                                          'in',
                                                          $range
                                                      ],
                                                      $morphType => $type,
                                                  ], $relation, $subRelation, $closure
                );
                // 关联属性名
                $attr = Loader::parseName($relation);
                // 关联数据封装
                foreach ($resultSet as $result) {
                    if (!isset($data[$result->$pk])) {
                        $data[$result->$pk] = [];
                    }
                    foreach ($data[$result->$pk] as &$relationModel) {
                        $relationModel->setParent(clone $result);
                        $relationModel->isUpdate(true);
                    }
                    $result->setRelation($attr, $this->resultSetBuild($data[$result->$pk]));
                }
            }
        }

        /**
         * 多态一对多 关联模型预查询
         * @access   public
         * @param array         $where       关联预查询条件
         * @param string        $relation    关联名
         * @param string        $subRelation 子关联
         * @param bool|\Closure $closure     闭包
         * @return array
         */
        protected function eagerlyMorphToMany($where, $relation, $subRelation = '', $closure = false) {
            // 预载入关联查询 支持嵌套预载入
            if ($closure) {
                call_user_func_array($closure, [& $this]);
            }
            $list     = $this->query->where($where)->with($subRelation)->select();
            $morphKey = $this->morphKey;
            // 组装模型数据
            $data = [];
            foreach ($list as $set) {
                $data[$set->$morphKey][] = $set;
            }
            return $data;
        }

        /**
         * 预载入关联查询
         * @access public
         * @param Model    $result      数据对象
         * @param string   $relation    当前关联名
         * @param string   $subRelation 子关联名
         * @param \Closure $closure     闭包
         * @return void
         */
        public function eagerlyResult(&$result, $relation, $subRelation, $closure) {
            $pk = $result->getPk();
            if (isset($result->$pk)) {
                $data = $this->eagerlyMorphToMany([
                                                      $this->morphKey  => $result->$pk,
                                                      $this->morphType => $this->type,
                                                  ], $relation, $subRelation, $closure
                );
                if (!isset($data[$result->$pk])) {
                    $data[$result->$pk] = [];
                }
                foreach ($data[$result->$pk] as &$relationModel) {
                    $relationModel->setParent(clone $result);
                    $relationModel->isUpdate(true);
                }
                $result->setRelation(Loader::parseName($relation), $this->resultSetBuild($data[$result->$pk]));
            }
        }

        /**
         * 关联统计
         * @access public
         * @param Model    $result  数据对象
         * @param \Closure $closure 闭包
         * @return integer
         */
        public function relationCount($result, $closure) {
            $pk    = $result->getPk();
            $count = 0;
            if (isset($result->$pk)) {
                if ($closure) {
                    call_user_func_array($closure, [& $this->query]);
                }
                $count = $this->query->where([
                                                 $this->morphKey  => $result->$pk,
                                                 $this->morphType => $this->type
                                             ]
                )->count();
            }
            return $count;
        }

        /**
         * 获取关联统计子查询
         * @access public
         * @param \Closure $closure 闭包
         * @return string
         */
        public function getRelationCountQuery($closure) {
            if ($closure) {
                call_user_func_array($closure, [& $this->query]);
            }
            return $this->query->where([
                                           $this->morphKey  => [
                                               'exp',
                                               '=' . $this->parent->getTable() . '.' . $this->parent->getPk(),
                                           ],
                                           $this->morphType => $this->type,
                                       ]
            )->fetchSql()->count();
        }

        /**
         * 批量保存当前关联数据对象
         * @access public
         * @param array $dataSet 数据集
         * @return integer
         */
        public function saveAll(array $dataSet) {
            $result = false;
            foreach ($dataSet as $key => $data) {
                $result = $this->save($data);
            }
            return $result;
        }

        /**
         * 保存（新增）当前关联数据对象
         * @access public
         * @param mixed $data 数据 可以使用数组 关联模型对象 和 关联对象的主键
         * @return Model|false
         */
        public function save($data) {
            if ($data instanceof Model) {
                $data = $data->getData();
            }
            // 保存关联表数据
            $pk                     = $this->parent->getPk();
            $model                  = new $this->model;
            $data[$this->morphKey]  = $this->parent->$pk;
            $data[$this->morphType] = $this->type;
            return $model->save($data) ? $model : false;
        }

        /**
         * 执行基础查询（进执行一次）
         * @access protected
         * @return void
         */
        protected function baseQuery() {
            if (empty($this->baseQuery) && $this->parent->getData()) {
                $pk                    = $this->parent->getPk();
                $map[$this->morphKey]  = $this->parent->$pk;
                $map[$this->morphType] = $this->type;
                $this->query->where($map);
                $this->baseQuery = true;
            }
        }
    }
